This study addresses vibro-acoustic problems [1] using Isogeometric Analysis (IGA) [2], a method well-suited for noise estimation in automotive and aerospace applications. A significant challenge in numerical analysis is the meshing of physical domains from Computer-Aided Design (CAD) files. IGA overcomes this issue by directly utilizing CAD representations. The originality of this work lies in the development of a methodology for solving linear vibro-acoustic problems using IGA. The proposed methodology follows these steps. First, the surface geometry is extracted from a CAD file, defined by control points, weights, and knot vectors, to enable a direct analysis based on shell theory. Next, the CAD surface is immersed [3] within a spline volume to construct an internal acoustic cavity and perform vibro-acoustic analyses. A key challenge is the coupling of non-matching geometries and physical models while integrating operators by leveraging the CAD surface boundary. This approach offers potential advantages by combining the accuracy and convergence properties of IGA in vibro-acoustic [4] with the direct use of CAD files (e.g., IGES or STEP), facilitating internal vibro-acoustic analysis. In this framework, acoustic cavity operators are computed from the volumetric domain, while structural operators are derived from the CAD surface. The coupling of these two physical domains leads to a fully coupled vibro-acoustic problem. The resulting eigenmodes and eigenvectors obtained from this approach are then compared with Finite Element Method (FEM) results and semi-analytical solutions.